1. The Field of the Invention
The present invention is related to a vehicle occupant restraint module. More particularly, the present invention is related to a novel airbag cushion restraint module with a unique collar for retaining the cushion in communication with a disk-shaped inflator.
2. Technical Background
Inflatable vehicle occupant safety restraint modules, or xe2x80x9cairbag modules,xe2x80x9d are mandatory on most new vehicles. Airbag modules commonly contain a collision sensor, an inflator, and an airbag cushion. In the event of an accident, a collision sensor such as an accelerometer, measures abnormal deceleration and triggers the inflator by means of an electronic signal. The inflator is a pyrotechnic device which produces gas or other inflation fluid. It is connected to the airbag cushion which is typically housed in the steering wheel on the driver""s side of a vehicle and in the dashboard on the passenger side of a vehicle. Airbag cushions are housed in an uninflated and folded condition to minimize space requirements. Upon receipt of the signal from the collision sensor, the inflator rapidly produces a quantity of inflation fluid or gas which inflates the cushion and protects the passenger from harmful impact with the interior of the car.
Most known passenger inflators are cylindrical and are mounted in a safety restraint module that is transverse to the vehicle occupant. These inflators require significant housing structures to support the inflator. They also require conduit or channeling structures to direct the inflation fluid from the inflator into the airbag cushion which is typically mounted separately and some distance from the inflator. The housing and conduit structures of these prior art cylindrical inflators are complex in their design, and are larger, heavier, and more costly to manufacture and install.
In response to these problems, smaller xe2x80x9cdisc stylexe2x80x9d inflators have been used. However, these inflators also suffer many disadvantages. Many disc style inflators are inappropriate for use on the passenger side of the vehicle because they lack the power to inflate the airbag cushion to adequately fill the space on the passenger side of the vehicle where there is no steering wheel. Other disc inflators have complex channeling designs for funnelling inflation fluid into the cushion. This adds to the complexity of the manufacturing process and also to the size and weight of the airbag module. These complex disk inflators are difficult to install.
Still other disk style inflators channel inflation fluid to small openings around the inflator which decreases the speed of inflation making the airbag restraint less effective on the passenger side of the vehicle. Still other disk inflators to not provide for even inflation of the airbag which can create unequal inflation forces causing the airbag cushion to be out of position upon inflation.
One problem with known airbag occupant restraint modules is that the inflation fluid source or inflator becomes very hot upon inflation of the airbag. Once the airbag has deployed and performed its purpose, airbag cushions ultimately collapse, and can come into contact with the inflator. This can damage the cushion or create harmful fumes as the cushion starts to burn.
Accordingly, a need exists for an airbag restraint module with a simplified, smaller, and lighter weight design that can also fully inflate an airbag cushion on the passenger side of the vehicle. Additionally, a need exists for such an airbag restraint module that provides for even inflation of the airbag cushion. Further, a need exists for such an airbag restraint module that can protect the cushion from heat damage during and after deployment. Still further, a need exists for an airbag module that can quickly deliver inflation fluid to the airbag without the need for complex channeling. Additionally, a need exists for an airbag restraint module that can accommodate the minimum width requirements due to front panel constraints on the vehicles dash board, while allowing for fast, even inflation. Such an novel airbag restraint module is disclosed and claimed herein.
The present invention is directed to a novel vehicle occupant restraint or airbag restraint module. The module includes an inflation fluid source, or inflator. The module also includes an inflatable cushion having an inner surface and an outer surface. The cushion is configured to receive inflation fluid generated by the inflator. The inflation fluid source comprises a plurality of openings circumferentially spaced about an outer surface of the inflation fluid source through which inflation fluid is directed out of the inflation fluid source.
A retaining collar maybe positioned to retain the cushion in communication with the inflation fluid source. In one embodiment, the retaining collar includes a flange flaring elliptically outward from the inflation fluid source. In this configuration, the retaining collar creates a larger area for the inflation fluid to flow into the cushion, while conforming to the width limitations of the inflator imposed by dashboard constraints. The elliptically extending flange also provides quick inflation without complex channeling of the inflation fluid. Accordingly, the retaining collar of the present invention is simplified, smaller, and lighter weight in design and can provide even inflation to fully inflate an airbag cushion on the passenger side of the vehicle.
The retaining collar flange may also include an extended portion or tab that extends axially beyond a distal end of the inflation fluid source when the retaining collar is secured about the inflation fluid source. The tab prevents the inflation cushion from direct contact with the inflation fluid source. Thus, the cushion is protected from burning by coming into contact with the hot inflator. In one embodiment, an outer edge of the flange extends axially beyond the fluid source openings which also protects the cushion from direct contact by hot gases produced by the inflation fluid source.
The cushion may include a mouth for receiving inflation fluid. In one embodiment, the mouth is configured to fit about an outer surface of the inflator. The retaining collar is positioned adjacent the inner surface of the cushion at the mouth of the cushion and about the outer surface of the inflation fluid source, thus keeping the cushion in communication with the inflator upon inflation. The retaining collar may include positioning extensions configured to engage the cushion to prevent the cushion from movement relative to the retaining collar.
These and other advantages of the present invention will become more fully apparent by examination of the following description of the preferred embodiments and the accompanying drawings.